In certain regions of the earth, for example in the U.S.A., long distances between zones with high average temperatures and zones with very low temperatures are covered by heavy duty motor trucks in intercity transport. Since heavy duty motor trucks are usually operated with diesel fuel, there is a problem that “normal diesel” fuel freezes at about −15° C. At lower temperatures, therefore, diesel powered vehicles have to be operated with another special fuel, what is known as “Arctic diesel”, which still remains liquid even at temperatures down to −40° C. However, Arctic diesel is approximately 10% to 15% more costly than normal diesel and, moreover, also gives rise to a fuel consumption which is about 10% to 15% higher. The aim, therefore, is to avoid operating the vehicle with Arctic diesel only, that is to say even in warmer regions. It is nevertheless impracticable and also not viable to change over the entire fuel system with tank or tanks and lines in the event of a change between warm and cold regions, that is to say to empty the tanks and refill them completely.
Heavy motor trucks are nowadays usually equipped with (at least) two fuel tanks. There is always the possibility, depending on the application, of filling the tanks with an identical or different types of fuel. With the aid of a valve arrangement of the type described in the introduction, the tanks can then be connected individually or jointly to the engine.
A known valve arrangement of the generic type mentioned is produced as a multivalve from metal and consists of a large number of individual parts screwed to one another, specifically of four 2/2-way valves (i.e. two-position two flow path valves) which are connected via two T-distributors. Each individual valve is designed as a ball valve and is operated mechanically via pull/push rods. This gives rise to some significant disadvantages:                long actuation travels of the lever mechanisms (150 to 160 mm)        high weight (approximately 2.5 kg)        screwed connections are not directionally adjustable or are directionally adjustable only with difficulty (with regard to the direction of run of connected lines)        high costs in terms of material and of assembly        high actuation force        only direct manual actuation possible, for which purpose the driver has to stop the vehicle and leave the driver's cab.        
The object on which the present invention is based is to provide a motorway valve arrangement of the type mentioned which is improved in order to avoid the disadvantages described and which is distinguished, in particular, by a reduced outlay in terms of material and of assembly, by low weight and by a low actuation force, along with the resulting possibility of automatic (remote) actuation.